Sex differences in pulse pressure trends with age are cross-cultural.

Sex differences in systolic and diastolic blood pressure levels and trends with age have been consistently observed in both industrialized and unindustrialized populations. However, the impact of sex on pulse pressure, an index of vascular aging, in unindustrialized populations has not been addressed. The objective of this report was to characterize sex differences in aging trends of pulse pressure within unindustrialized populations. Using PubMed and Medline, we identified 60 articles with blood pressure data from unacculturated or partially acculturated populations. Data on 27 populations from 22 articles were included for analysis, on the basis of adequate description of study design and blood pressure measurement. Blood pressure means of adult age groups were modeled by linear and polynomial regression. The pulse pressure levels of women were lower than those of men in early adulthood and higher in older ages. Women had a steeper, steady increase in pulse pressure with age than men (P<0.001), whereas men had a stronger curvilinear upswing in pulse pressure with age (P=0.006). Partially acculturated populations had higher pulse pressures than unacculturated populations. Sex had a stronger effect on pulse pressure than acculturation. Pulse pressure trajectories of unindustrialized populations were slightly attenuated compared with those seen in National Health and Nutritional Examination Surveys III and IV of the US population. A sex effect on pulse pressure trends with age prevails across unacculturated and acculturated populations. Accordingly, the biological principles of arterial aging, as expressed in pulse pressure, are the same in all humans, regardless of demography.

[Nitrite test in Pseudomonas aeruginosa urinary tract infections].

UNLABELLED: Pseudomonas aeruginosa (PA) is considered to be bacteria with a low capability to produce nitrite. OBJECTIVE: To investigate the incidence of a positive urine nitrite test in community-acquired urinary tract infections (UTI) in children, caused by PA. METHODS: The medical records of 38 children (18 females) admitted for febrile PA UTI during a period of 7 years were reviewed. Urine nitrite tests were carried out using dipstrips, and results were reported as positive or negative. RESULTS: Of the 38 patients, 17 had a positive nitrite test and 21 had a negative test (proportion of positive 0.45, 95% confidence interval 0.29 to 0.61). Pyuria was detected in 13/17 patients with a positive nitrate test vs. 5/21 with a negative test (p=0.003). Data regarding renal ultrasound (US) were available for 35 patients, and in 20 abnormalities were detected, 14/17 in the positive vs. 6/18 in negative nitrite group (p = 0.001). CONCLUSION: The urine nitrite test may be positive in PA UTI, therefore, a positive test does not rule out Pseudomonas UTI.

Renal and gastrointestinal potassium excretion in humans: new insight based on new data and review and analysis of published studies.

OBJECTIVES: Little is known about the relationship between the renal and gastrointestinal excretion of potassium in humans. This information is important in light of strong associations of potassium intake with hypertension and occlusive stroke. METHODS: We determined the relationship between fecal and urinary excretion of potassium under both fixed and variable potassium intakes using our unpublished archival data and published data of others. Twenty-five subjects were evaluated. RESULTS: On a fixed, low oral potassium intake (61.2 +/- 4.7 mmol/day; mean +/- SD), there was an inverse relationship between fecal and urinary potassium excretion (r = -0.66, p = 0.040). In studies in which potassium intake varied between 61-135 mmol/day, fecal and urinary potassium excretions were positively correlated (r = 0.58, p = 0.024). Considerable within-and-between-subject variation was observed in the relationship between fecal and urinary potassium excretion. CONCLUSIONS: Inter-individual variation in fecal potassium excretion may arise from both variation in dietary potassium intake and intrinsic individual differences in the renal versus gastrointestinal handling of potassium.

Renal functional deterioration is not affected by the magnitude of sodium consumption in a normotensive model of moderate renal failure.

BACKGROUND/AIMS: High sodium consumption has been repeatedly reported to exert deleterious effects on severe chronic renal failure progression, mainly via glomerular mechanisms. However, the role of high sodium intake in renal function deterioration in a model of moderate chronic tubulointerstitial disease has not yet been addressed. We evaluated the effects of exaggerated dietary sodium and the resultant increase in proteinuria on renal function deterioration in experimental tubulointerstitial disease in rats. METHODS: In 48 Sprague-Dawley rats, moderate renal failure (approximately 50% of normal glomerular filtration rate) was induced by administration of lithium chloride in drinking water. The animals were divided into three groups fed low (<0.2% Na(+)), normal (0.5% Na(+)), or high (8% Na(+)) sodium diets. RESULTS: Animals in all groups remained normotensive with a similar course of GFR downslope and 100% survival, irrespective of sodium regimen. Rats consuming high sodium diets developed significantly greater proteinuria compared to their counterparts fed normal or low sodium chow. CONCLUSIONS: (1) Deterioration of renal function in a lithium-induced model of normotensive moderate chronic renal failure was not affected by dietary sodium. (2) Unlike in some other human or experimental renal failure models, the magnitude of proteinuria had no adverse effect on the progression of renal deterioration.

Symptomatic urinary tract infections following voiding cystourethrography.

The objective of this study was to assess the frequency of symptomatic urinary tract infections (UTIs) following voiding cystourethrography (VCUG) while using prophylactic antibiotics. Medical records of 421 patients who underwent a VCUG during a period of 4 years were reviewed. Three hundred forty-nine had a VCUG following a febrile UTI, and 72 had the test for evaluation of hydronephrosis. All received prophylactic antibiotics and were evaluated within 7-10 days following the VCUG. One hundred seventy-two children (41%) had an abnormal VCUG. Seven of 421 children (1.7%) had symptoms suggestive of UTI. Two had culture negative pyuria; one had Escherichia Coli UTI, and four had Pseudomonas aeruginosa UTI. On multivariate logistic regression analysis, the risk factors contributing to the development of UTI following VCUG were the presence of vesicoureteral reflux (VUR) and its severity (odds ratio [OR] 2.52; 95% confidence interval [CI] 2.24, 2.83, p =0.001; and OR 2.32; 95% CI 2.05,2.62, p =0.04, respectively). The incidence of VCUG-induced UTI in children receiving prophylactic antibiotic therapy is low. There is a relatively high rate of Pseudomonas UTI, especially in children with moderate to severe reflux. We recommend that children with symptoms suggesting a UTI following a VCUG should be treated for Pseudomonas aeruginosa pending culture results.

Control of hypertension with captopril affords better renal protection as compared with irbesartan in salt-loaded uremic rats.

BACKGROUND/AIM: Hypertension induced by exaggerated sodium consumption accelerates the progression of renal failure. We investigated the effects of a high-sodium (HS) diet on the progression of renal failure in rats maintained normotensive by angiotensin-converting enzyme inhibition or AT-1 blockade. METHODS: In 70 Sprague-Dawley rats, renal failure was induced by five-sixths nephrectomy. They were fed isocaloric normal-sodium (NS), low-sodium (LS), or HS diets. HS rats prone to develop hypertension were divided into three subgroups: treated to normotension by irbesartan (HS-1) or captopril (HS-2) or left untreated (HS-0). RESULTS: All HS animals developed significant proteinuria which strongly correlated with the 24-hour sodium excretion. HS-0 rats demonstrated severe hypertension, rapid deterioration of the renal function, and 100% mortality after 3 weeks. In irbesartan-treated HS-1 rats, mortality and decline of the glomerular filtration rate were similar to those of normal- or low-sodium-fed animals (100% mortality after week 12). In captopril-treated HS-2 rats, glomerular filtration rate decline and mortality were significantly blunted as compared with all other groups (50% mortality after week 12). CONCLUSIONS: (1) In five-sixths-nephrectomized uremic rats maintained normotensive by either irbesartan or captopril, the rate of deterioration of the renal function was not aggravated by exaggerated sodium consumption. (2) In this experimental setting, captopril treatment yielded a better survival outcome as compared with irbesartan, despite the similar hypotensive effect.